Biometric techniques for determining the identity of individuals, such as in security applications, have been well known and in use for some time. To date, biometric techniques have primarily been oriented towards fingerprint analysis rather than the visual recognition of facial images. Identification using infrared thermal imaging has been a more recent phenomena. For example, Rice, in U.S. Pat. No. 4,699,149, taught the scanning of subcutaneous blood vessels by measuring the inflection of incident radiation as a technique for determining a person's identification signature. However, active heating of the area being scanned was required in order to get an accurate scan. More recently, the Prokcski et al. patent, U.S. Pat. No. 5,163,094, moved the infrared field forward by describing a method and apparatus for identifying individuals characterized by analyzing elemental shapes from thermally derived biosensor data. Thermal images are converted into digital representations by measuring the intensity of each pixel corresponding to the level of thermal energy for a corresponding portion of the image. Following standardization, an image containing the elemental shapes can be compared and then correlated with unique structural features of an individual.
However, several aspects of the systems have not been dealt with: automatically positioning a camera or other, biosensor, enhancing identification accuracy through class sorting, and identifying individual facial features from those subjects wearing eyeglasses.